The present invention relates to apparatus for heat-treating or steam-setting bobbins of yarn produced by a spinning machine as the bobbins are transferred from the spinning machine to a winding machine.
In the spinning process, sliver of raw cotton, wool and synthetic fiber are spun into yarn which is wound on bobbins. The finished yarn on the bobbins is then wound by the winding machine into a so-called corn cheese or parallel cheese for the next process. This winding process of winding the yarn on a plurality of bobbins into a single parallel cheese or corn cheese requires the yarn ends to be joined.
The spun yarn produced by the spinning machine has a twisting torque which must be removed to obtain a stable quality of yarn. For this purpose, the bobbins of yarn are heat-treated, particularly, by steam. The steam heat treatment is important also in the yarn end joining process in the winding machine.
In the yarn end joining process, the ends of the spun yarn are drawn out by a carrier air flow and guided by the guide of the yarn end joining device where they are automatically joined. If there is a twisting torque in the spun yarn, the ends of the drawn yarn are not aligned in the direction of the carrier air flow direction, resulting in the yarn ends failing to be joined. For this reason, the bobbins of finished yarn are steam-set before being fed to the winding machine to remove the twisting torque.
Conventionally, the bobbins are randomly thrown into bobbin cases and several tens of these bobbin cases are loaded into an oven where they are heat-treated by steam.
In such a batch steam heat treatment process, the bobbins of spun yarn produced by the spinning machine are loaded into bobbin cases which are transported into the steam heat treatment room where a heat treatment oven is installed. The bobbin cases are placed in the steam oven and heated at a certain temperature for a prescribed period of time. After being heat-treated, the bobbin cases are carried to the winding machine where the bobbins are attached to the spindles of the winding machine.
In such a steam heat treatment procedure, the process of removing the bobbins from the spinning machine and that of fitting the bobbins on the winding machine are each automated independently. However, these processes require a transport path to carry a certain quantity of bobbins to the steam oven, load them into the oven for steam setting, and carry the heat-treated bobbins to the winding machine for winding on the spindles.
In other words, because the steam heat treatment process is provided independently of the spinning machine and the winding machine, the conventional bobbin heat treatment method requires at least five devices, i.e., a spinning machine, a carrying device, a steam heat treatment device, another carrying device, and a winding machine.
From the construction of the above-mentioned apparatus, the following processes are required: a preparatory process of loading a certain number of bobbins into each of the bobbin cases for transfer to the steam heat treatment device, a process of loading the bobbin cases into the steam heat treatment device for heat treatment, and a process of unloading the cases of heat-treated bobbins from the heat treatment device. These separate processes make the bobbin heat treatment process complicated and thus are the major obstacles in the way to an automated continuous series of processings. The essential point of this problem is the fact that the steam heat treatment process is independent of the spinning process and the winding process.
Although the temperature and time required for the vacuum heat treatment somewhat vary depending on the kind of yarn wound on the bobbins, such as whether the yarn is made of wool, cotton or mixed stuff with synthetic fiber, the following problems arise with the conventional steam heat treatment apparatus when the number of bobbins to be processed in a unit of time increases.
That is, the conventional steam heat treatment apparatus is designed to be installed between the spinning machine and the winding machine and is large in size, so that it is practically impossible to connect it to the spinning machine or winding machine.